Research

12 pages, 4455 KiB

Open AccessArticle

In Vitro Testing and Clinical Handling of a Novel Implant Positioning Technology for Proximal Humeral Plating

by Markus Windolf, Dominik Knierzinger, Stefaan Nijs, An Sermon, Michael Blauth, Robert Geoff Richards and Jan Buschbaum

Medicina 2023, 59(3), 450; https://doi.org/10.3390/medicina59030450 - 23 Feb 2023

Viewed by 1298

Abstract

Background and Objectives: Fractures of the proximal humerus are common, particularly in elderly populations. Anatomical locking plates target stabilization with a multitude of screws spanning into the humeral head. Sound implant placement and screw length determination are key for a successful clinical outcome [...] Read more.

Background and Objectives: Fractures of the proximal humerus are common, particularly in elderly populations. Anatomical locking plates target stabilization with a multitude of screws spanning into the humeral head. Sound implant placement and screw length determination are key for a successful clinical outcome but are difficult to obtain from planar X-rays. A novel implant positioning technology for proximal humerus plating (Xin1) outputs screw lengths suggestions and plate position based on hole projections in conventional X-ray images. This study investigated the performance of a prototype Xin1 system in a postmortem (in vitro) experiment as well as in a clinical handling test. Materials and Methods: For in vitro testing, twelve shoulders from six anatomical specimens were randomized into two groups to compare the Xin1 technique to the conventional operation in terms of surgical precision, procedure time and X-ray exposure. For the clinical trial, 11 patients undergoing plating of the proximal humerus were included. The aim was to investigate clinical handling of the Xin1 marker clip and to retrospectively evaluate the system performance in a real-life fracture situation. Image pairs before and after insertion of the proximal screws were retrospectively processed to investigate the influence of potential bone fragment shifts on the system output. Results: In the postmortem experiment, the use of the system significantly improved the surgical precision (52% error reduction), procedure time (38% shorter) and radiation exposure (64% less X-rays). Clinical handling demonstrated seamless embedding of the marker clip into existing clinical workflows without adverse events reported. Retrospective X-ray analysis on six eligible patients revealed differences in the calculated screw lengths of ≤2 mm before and after screw insertion for five patients. In one patient, the screw lengths differed up to 8 mm, which might indicate displacement of the head fragment. Conclusions: Results suggest a strong potential of the Xin1 assistance technology to enhance the surgical procedure and patient outcomes in the rising incidence of osteoporotic humeral fractures. Robust performance in a real-life fracture situation was observed. In-depth validation of the system is, however, needed before placing it into clinical practice. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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11 pages, 1583 KiB

Open AccessArticle

Patient-Specific Guides for Accurate and Precise Positioning of Osseointegrated Implants in Transfemoral Amputations: A Proof-of-Concept In Vitro Study

by Emir Benca, Beatrice Ferrante, Ewald Unger, Andreas Strassl, Lena Hirtler, Rickard Brånemark, Reinhard Windhager and Gerhard M. Hobusch

Medicina 2023, 59(3), 429; https://doi.org/10.3390/medicina59030429 - 22 Feb 2023

Cited by 1 | Viewed by 1428

Abstract

Background and Objectives: The treatment of transfemoral amputees using osseointegrated implants for prosthetic anchorage requires accurate implant positioning when using threaded bone-anchoring implants due to the curvature of the femur and the risk of cortical penetration in misaligned implants. This study investigated [...] Read more.

Background and Objectives: The treatment of transfemoral amputees using osseointegrated implants for prosthetic anchorage requires accurate implant positioning when using threaded bone-anchoring implants due to the curvature of the femur and the risk of cortical penetration in misaligned implants. This study investigated the accuracy and precision in implant positioning using additively manufactured case-specific positioning guides. Materials and Methods: The geometry and density distribution of twenty anatomic specimens of human femora were assessed in quantitative computed tomography (QCT) scanning. The imaging series were used to create digital 3D specimen models, preoperatively plan the optimal implant position and manufacture specimen-specific positioning guides. Following the surgical bone preparation and insertion of the fixture (threaded bone-anchoring element) (OPRA; Integrum AB, Mölndal, Sweden), a second QCT imaging series and 3D model design were conducted to assess the operatively achieved implant position. The 3D models were registered and the deviations of the intraoperatively achieved implant position from the preoperatively planned implant position were analyzed as follows. The achieved, compared to the planned implant position, was presented as resulting mean hip abduction or adduction (A/A) and extension or flexion (E/F) and mean implant axis offset in medial or lateral (M/L) and anterior or posterior (A/P) direction measured at the most distal implant axis point. Results: The achieved implant position deviated from the preoperative plan by 0.33 ± 0.33° (A/A) and 0.68 ± 0.66° (E/F) and 0.62 ± 0.55 mm (M/L) and 0.68 ± 0.56 mm (A/P), respectively. Conclusions: Using case-specific guides, it was feasible to achieve not only accurate but also precise positioning of the implants compared to the preoperative plan. Thus, their design and application in the clinical routine should be considered, especially in absence of viable alternatives. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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10 pages, 1997 KiB

Open AccessArticle

“Bring Your Own Device”—A New Approach to Wearable Outcome Assessment in Trauma

by Benedikt J. Braun, Tina Histing, Maximilian M. Menger, Julian Platte, Bernd Grimm, Andrew M. Hanflik, Peter H. Richter, Sureshan Sivananthan, Seth R. Yarboro, Boyko Gueorguiev, Dmitry Pokhvashchev and Meir T. Marmor

Medicina 2023, 59(2), 403; https://doi.org/10.3390/medicina59020403 - 19 Feb 2023

Cited by 2 | Viewed by 1653

Abstract

Background and Objectives: Outcome data from wearable devices are increasingly used in both research and clinics. Traditionally, a dedicated device is chosen for a given study or clinical application to collect outcome data as soon as the patient is included in a [...] Read more.

Background and Objectives: Outcome data from wearable devices are increasingly used in both research and clinics. Traditionally, a dedicated device is chosen for a given study or clinical application to collect outcome data as soon as the patient is included in a study or undergoes a procedure. The current study introduces a new measurement strategy, whereby patients’ own devices are utilized, allowing for both a pre-injury baseline measure and ability to show achievable results. Materials and Methods: Patients with a pre-existing musculoskeletal injury of the upper and lower extremity were included in this exploratory, proof-of-concept study. They were followed up for a minimum of 6 weeks after injury, and their wearable outcome data (from a smartphone and/or a body-worn sensor) were continuously acquired during this period. A descriptive analysis of the screening characteristics and the observed and achievable outcome patterns was performed. Results: A total of 432 patients was continuously screened for the study, and their screening was analyzed. The highest success rate for successful inclusion was in younger patients. Forty-eight patients were included in the analysis. The most prevalent outcome was step count. Three distinctive activity data patterns were observed: patients recovering, patients with slow or no recovery, and patients needing additional measures to determine treatment outcomes. Conclusions: Measuring outcomes in trauma patients with the Bring Your Own Device (BYOD) strategy is feasible. With this approach, patients were able to provide continuous activity data without any dedicated equipment given to them. The measurement technique is especially suited to particular patient groups. Our study’s screening log and inclusion characteristics can help inform future studies wishing to employ the BYOD design. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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14 pages, 2756 KiB

Open AccessArticle

Third-Generation Dynamic Anterior Plate-Screw System for Quadrilateral Fractures: Digital Design Based on 834 Pelvic Measurements

by Ranran Shang, Haiyang Wu, Li Zhou, Chengjing Song, Qipeng Shao, Ximing Liu and Xianhua Cai

Medicina 2023, 59(2), 211; https://doi.org/10.3390/medicina59020211 - 21 Jan 2023

Cited by 1 | Viewed by 1402

Abstract

Background and Objectives: To investigate the digital measurement method for the plate trajectory of dynamic anterior plate-screw system for quadrilateral plate (DAPSQ), and then design a third-generation DAPSQ plate that conforms to the needs of the Chinese population through collating a large [...] Read more.

Background and Objectives: To investigate the digital measurement method for the plate trajectory of dynamic anterior plate-screw system for quadrilateral plate (DAPSQ), and then design a third-generation DAPSQ plate that conforms to the needs of the Chinese population through collating a large sample anatomical data. Materials and Methods: Firstly, the length of the pubic region, quadrilateral region, iliac region, and the total length of the DAPSQ trajectory were measured by a digital measurement approach in 22 complete pelvic specimens. Then, the results were compared with the direct measurement of pelvic specimens to verify the reliability of the digital measurement method. Secondly, 504 cases (834 hemilateral pelvis) of adult pelvic CT images were collected from four medical centers in China. The four DAPSQ trajectory parameters were obtained with the digital measurement method. Finally, the third-generation DAPSQ plate was designed, and its applicability was verified. Results: There was no statistically significant difference in the four trajectory parameters when comparing the direct measurement method with the digital measurement method (p > 0.05). The average lengths of the pubic region, quadrilateral region, iliac region, and the total length in Chinese population were (60.96 ± 5.39) mm, (69.11 ± 5.28) mm, (84.40 ± 6.41) mm, and (214.46 ± 10.15) mm, respectively. Based on the measurement results, six models of the DAPSQ plate including small size (A1,A2), medium size (B1,B2), and the large size (C1,C2) were designed. The verification experiment showed that all these six type plates could meet the requirement of 94.36% cases. Conclusions: A reliable computerized method for measuring irregular pelvic structure was proposed, which not only provided an anatomical basis for the design of the third-generation DAPSQ plate, but also provided a reference for the design of other pelvic fixation devices. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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12 pages, 3672 KiB

Open AccessArticle

Artificial Intelligence Accurately Detects Traumatic Thoracolumbar Fractures on Sagittal Radiographs

by Guillermo Sánchez Rosenberg, Andrea Cina, Giuseppe Rosario Schiró, Pietro Domenico Giorgi, Boyko Gueorguiev, Mauro Alini, Peter Varga, Fabio Galbusera and Enrico Gallazzi

Medicina 2022, 58(8), 998; https://doi.org/10.3390/medicina58080998 - 26 Jul 2022

Cited by 7 | Viewed by 2200

Abstract

Background and Objectives: Commonly being the first step in trauma routine imaging, up to 67% fractures are missed on plain radiographs of the thoracolumbar (TL) spine. The aim of this study was to develop a deep learning model that detects traumatic fractures [...] Read more.

Background and Objectives: Commonly being the first step in trauma routine imaging, up to 67% fractures are missed on plain radiographs of the thoracolumbar (TL) spine. The aim of this study was to develop a deep learning model that detects traumatic fractures on sagittal radiographs of the TL spine. Identifying vertebral fractures in simple radiographic projections would have a significant clinical and financial impact, especially for low- and middle-income countries where computed tomography (CT) and magnetic resonance imaging (MRI) are not readily available and could help select patients that need second level imaging, thus improving the cost-effectiveness. Materials and Methods: Imaging studies (radiographs, CT, and/or MRI) of 151 patients were used. An expert group of three spinal surgeons reviewed all available images to confirm presence and type of fractures. In total, 630 single vertebra images were extracted from the sagittal radiographs of the 151 patients—302 exhibiting a vertebral body fracture, and 328 exhibiting no fracture. Following augmentation, these single vertebra images were used to train, validate, and comparatively test two deep learning convolutional neural network models, namely ResNet18 and VGG16. A heatmap analysis was then conducted to better understand the predictions of each model. Results: ResNet18 demonstrated a better performance, achieving higher sensitivity (91%), specificity (89%), and accuracy (88%) compared to VGG16 (90%, 83%, 86%). In 81% of the cases, the “warm zone” in the heatmaps correlated with the findings, suggestive of fracture within the vertebral body seen in the imaging studies. Vertebras T12 to L2 were the most frequently involved, accounting for 48% of the fractures. A4, A3, and A1 were the most frequent fracture types according to the AO Spine Classification. Conclusions: ResNet18 could accurately identify the traumatic vertebral fractures on the TL sagittal radiographs. In most cases, the model based its prediction on the same areas that human expert classifiers used to determine the presence of a fracture. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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14 pages, 5627 KiB

Open AccessArticle

Continuous Rod Load Monitoring to Assess Spinal Fusion Status–Pilot In Vivo Data in Sheep

by Markus Windolf, Maximilian Heumann, Viktor Varjas, Caroline Constant, Manuela Ernst, Robert Geoff Richards, Hans-Joachim Wilke and Lorin Michael Benneker

Medicina 2022, 58(7), 899; https://doi.org/10.3390/medicina58070899 - 06 Jul 2022

Cited by 7 | Viewed by 2148

Abstract

Background and Objectives: Spinal fusion is an effective and widely accepted intervention. However, complications such as non-unions and hardware failures are frequently observed. Radiologic imaging and physical examination are still the gold standards in the assessment of spinal fusion, despite multiple limitations [...] Read more.

Background and Objectives: Spinal fusion is an effective and widely accepted intervention. However, complications such as non-unions and hardware failures are frequently observed. Radiologic imaging and physical examination are still the gold standards in the assessment of spinal fusion, despite multiple limitations including radiation exposure and subjective image interpretation. Furthermore, current diagnostic methods only allow fusion assessment at certain time points and require the patient’s presence at the hospital or medical practice. A recently introduced implantable sensor system for continuous and wireless implant load monitoring in trauma applications carries the potential to overcome these drawbacks, but transferability of the principle to the spine has not been demonstrated yet. Materials and Methods: The existing trauma sensor was modified for attachment to a standard pedicle-screw-rod system. Two lumbar segments (L2 to L4) of one Swiss white alpine sheep were asymmetrically instrumented. After facetectomy, three sensors were attached to the rods between each screw pair and activated for measurement. The sheep was euthanized 16 weeks postoperatively. After radiological assessment the spine was explanted and loaded in flexion-extension to determine the range of motion of the spinal segments. Sensor data were compared with mechanical test results and radiologic findings. Results: The sensors measured physiological rod loading autonomously over the observation period and delivered the data daily to bonded smartphones. At euthanasia the relative rod load dropped to 67% of the respective maximum value for the L23 segment and to 30% for the L34 segment. In agreement, the total range of motion of both operated segments was lower compared to an intact reference segment (L23: 0.57°; L34: 0.49°; intact L45: 4.17°). Radiologic assessment revealed fusion mass in the facet joint gaps and bilateral bridging bone around the joints at both operated segments. Conclusions: Observations of this single-case study confirm the basic ability of continuous rod load measurement to resolve the spinal fusion process as indicated by a declining rod load with progressing bone fusion. A strong clinical potential of such technology is eminent, but further data must be collected for final proof of principle. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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16 pages, 3415 KiB

Open AccessArticle

Continuous Implant Load Monitoring to Assess Bone Healing Status—Evidence from Animal Testing

by Markus Windolf, Viktor Varjas, Dominic Gehweiler, Ronald Schwyn, Daniel Arens, Caroline Constant, Stephan Zeiter, Robert Geoff Richards and Manuela Ernst

Medicina 2022, 58(7), 858; https://doi.org/10.3390/medicina58070858 - 27 Jun 2022

Cited by 15 | Viewed by 2787

Abstract

Background and Objectives: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide snapshots in time, which are limited due to logistics and radiation exposure. We recently proposed assessing the bone [...] Read more.

Background and Objectives: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide snapshots in time, which are limited due to logistics and radiation exposure. We recently proposed assessing the bone healing status through continuous monitoring of the implant load, utilizing an implanted sensor system, the Fracture Monitor. The device telemetrically transmits statistically derived implant parameters via the patient’s mobile phone to assist physicians in diagnostics and treatment decision-making. This preclinical study aims to systematically investigate the device safety and performance in an animal setting. Materials and Methods: Mid-shaft tibial osteotomies of different sizes (0.6–30 mm) were created in eleven Swiss mountain sheep. The bones were stabilized with either a conventional Titanium or stainless-steel locking plate equipped with a Fracture Monitor. Data were continuously collected over the device’s lifetime. Conventional radiographs and clinical CT scans were taken longitudinally over the study period. The radiographs were systematically scored and CTs were evaluated for normalized bone volume in the defect. The animals were euthanized after 9 months. The sensor output was correlated with the radiologic parameters. Tissue samples from the device location were histologically examined. Results: The sensors functioned autonomously for 6.5–8.4 months until energy depletion. No macroscopic or microscopic adverse effects from device implantation were observed. The relative implant loads at 4 and 8 weeks post-operation correlated significantly with the radiographic scores and with the normalized bone volume metric. Conclusions: Continuous implant load monitoring appears as a relevant approach to support and objectify fracture healing assessments and carries a strong potential to enable patient-tailored rehabilitation in the future. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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11 pages, 1787 KiB

Open AccessArticle

Three-Dimensional Planning and Patient-Specific Instrumentation for the Fixation of Distal Radius Fractures

by Tatjana Pastor, Ladislav Nagy, Philipp Fürnstahl, Simon Roner, Torsten Pastor and Andreas Schweizer

Medicina 2022, 58(6), 744; https://doi.org/10.3390/medicina58060744 - 30 May 2022

Cited by 11 | Viewed by 2304

Abstract

Background and Objectives: Three-dimensional planning and guided osteotomy utilizing patient-specific instrumentation (PSI) with the contralateral side used as a reference have been proven as effective in the treatment of malunions following complex fractures of the distal radius. However, this approach has not [...] Read more.

Background and Objectives: Three-dimensional planning and guided osteotomy utilizing patient-specific instrumentation (PSI) with the contralateral side used as a reference have been proven as effective in the treatment of malunions following complex fractures of the distal radius. However, this approach has not yet been described in relation to fracture reduction of the distal radius. The aim of this study was to assess the technical and logistical feasibility of computer-assisted surgery in a clinical setting using PSI for fracture reduction and fixation. Materials and Methods: Five patients with varied fracture patterns of the distal radius underwent operative treatment with using PSI. The first applied PSI guide allowed specific and accurate placement of Kirschner wires inside the multiple fragments, with subsequent concurrent reduction using a second guide. Results: Planning, printing of the guides, and operations were performed within 5.6 days on average (range of 1–10 days). All patients could be treated within a reasonable period of time, demonstrating good outcomes, and were able to return to work after a follow-up of three months. Mean wrist movements (°) were 58 (standard deviation (SD) 21) in flexion, 62 (SD 15) in extension, 73 (SD 4) in pronation and 74 (SD 10) in supination at a minimum follow-up of 6 months. Conclusions: Three-dimensional planned osteosynthesis using PSI for treatment of distal radius fractures is feasible and facilitates reduction of multiple fracture fragments. However, higher costs must be taken into consideration for this treatment. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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7 pages, 1951 KiB

Open AccessArticle

Improved Fixation Stability of a Dedicated Rib Fixation System in Flail Chest: A Retrospective Study

by Shang-Ting Tsai, Hung-Yu Lin, Chia-Ying Li and Chih-Chien Lin

Medicina 2022, 58(3), 345; https://doi.org/10.3390/medicina58030345 - 24 Feb 2022

Viewed by 4508

Abstract

Background and Objectives: Flail chest typically results from major trauma to the thoracic cage and is accompanied by multiple rib fractures. It has been well documented that surgical fixation of rib fractures can decrease both morbidity and mortality rates. This study aimed [...] Read more.

Background and Objectives: Flail chest typically results from major trauma to the thoracic cage and is accompanied by multiple rib fractures. It has been well documented that surgical fixation of rib fractures can decrease both morbidity and mortality rates. This study aimed to evaluate the effectiveness of a dedicated APS Rib Fixation System, which features a pre-contoured design based on anatomical rib data of the Asian population. Materials and Methods: We reviewed 43 consecutive patients, who underwent surgical stabilization for flail chest with the traditional Mini bone plate (n = 20), APS plate (n = 13), or Mini + APS (n = 10). Demographic and injury variables were documented. We used X-ray radiography to determine plate fractures and screw dislocations after surgical fixation. Results: No statistical differences were noted in the demographic or injury variables. APS plates demonstrated fewer cases of plate fractures and screw dislocations than Mini plates (OR = 0.091, p = 0.008). Conclusions: The pre-contoured design of the APS plate demonstrated a superior rib implant failure rate as compared to the traditional Mini bone plate. Our study indicates that the APS plate may serve as an effective surgical tool for the treatment of flail chest. Full article

(This article belongs to the Special Issue Digital Trends in the Field of Orthopaedic Implant Research and Development)

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